How you can install any fonts in the Microsoft Word?

You don't really install fonts for Word, you install fonts for Windows. These fonts are then available for ANY program installed on your computer.

Font files usually have an extension TTF (this means it is a font file of the "TrueType" kind). Just copy the font files to the Fonts folder in Windows. Note that font files may be subject to copyright, so if you didn't pay for it, possibly you don't have the right to use it.